From DE 10 2013 002 605 A1, the content of which is hereby incorporated herein in its entirety, the fundamental construction of a turbocharger is known. A turbocharger comprises a turbine in which a first medium is expanded. A turbocharger, furthermore, comprises a compressor in which a second medium is compressed, namely utilising the energy extracted in the turbine during the expansion of the first medium. The turbine of the turbocharger comprises a turbine housing and a turbine rotor. The compressor of the turbocharger comprises a compressor housing and a compressor rotor. Between the turbine housing of the turbine and the compressor housing of the compressor, a bearing housing is positioned, wherein the bearing housing on the one hand is connected to the turbine housing and on the other hand to the compressor housing. In the bearing housing, a shaft is mounted via which the turbine rotor is coupled to the compressor rotor.
From practice it is known that the shaft which couples the turbine rotor of the turbine to the compressor rotor of the compressor is mounted in the bearing housing via at least one bearing. The respective bearing of the bearing housing for mounting the shaft comprises a bearing bush, which can either be mounted in a rotationally fixed manner or rotate in the bearing housing. The present invention relates to a turbocharger, in the case of which in the region of at least one bearing of the bearing housing, the bearing bush of the bearing is mounted in the bearing housing in a rotationally fixed manner. Between the bearing housing and the bearing bush a radially outer lubricating gap and between the bearing bush and the shaft a radially inner lubricating gap are formed. The radially outer lubricating gap formed between the bearing housing and the bearing bush is also referred to as squeeze film dampers.
In turbochargers known from practice, the respective bearing of the bearing housing is fixed in its axial position in the bearing housing because of the fact that the respective bearing bush, with a first axial end, interacts with a stop provided by the bearing housing, and because of the fact that the axial end of the bearing bush located opposite interacts with a cover. The axial end faces of the bearing bush, which are formed at the axial ends of the bearing bush and are located opposite either the stop of the bearing housing or the cover, are formed in turbochargers known from practice in such a manner that the same extend perpendicularly relative to the axial direction of the bearing bush throughout. Accordingly, the respective bearing bush via its axial end faces comes to lie in each case with the full surface area against the shoulder of the bearing housing and the cover. In order to avoid excessive friction between the axial end faces of the bearing bush and the stop of the bearing housing or the cover, a defined axial gap is adjusted between the axial end faces of the bearing bush and the stop of the bearing housing as well as the cover, which however results in oil losses in particular in the region of the radially outer lubricating gap functioning as squeeze film damper.